Joseph bidge



(No Model.)

J. RIDGE.

Y MUPPLEB, FOR SCHOOL SLATVES'. No. 294,154'. r Patented Feb. '26, 1884`g.) @yimg the material used for Inuiiling slates.

UNITED STA-TES PATENT OFFICE JOsErH RIDGE, OE OHIOAGO, ILLINOIS,AssIGNOE To JOHnT H. BEEEs, or

' sAME PLAGE.

MUFFLER FOR SCHOOL-SLATES.

SPECIFICATION forming part of Letters Fatent No. 294,154, dated February26, 1884.

' i Application I'iled November 5, 1883. (No model.)

To all whom t may concern,.-

Be it known that I, JOSEPH RIDGE, of Chicago, county of Cook, and StateOfIllinois,have invented new and useful Improvements in Mufflers forSehool-Slates, of which the following is a full and completedescription, reference being had to the accompanying drawings.

My invention relates to a radical change in Heretofore it has been thecustom to rely upon softarticles-such as rubber or a textile material-inwhich the eompressible nature of the material itself affords theproperties that serve to deaden the sound. The objection to suchmaterial is the cost and'lack of durability.

To obviate these obj ections I have substitutedV a spring-that is, ahardsubstance whose ilexible elasticity relieves the solid andnoise-producing contact of an unmufiled slate. In' the present examplethe material employed is strips of rattan, or, rather, what is known ascane, being the same as used in the manufacture of chairs and otherfurniture, which is, perhaps, less expensive, considering its qualities,than anything else, though wire or a wooden or metallic splint or ribboncan be used. I also show in the drawings a modification ofwhat Iconsiderv the preferable plan or" mnflling, in which a wooden strip islaced to theouter edge of the slate-frame in such a manner as toestablish a flexible connection between the latter and said strip, inwhich I have used the cane as a lacing material,though a textile cord orother fabric may serve the saine purpose.

In the drawings, Figure 1 is a side view of a section of a slate with myimprovement attached. Fig. 2 is an edge view of the same. Fig. 3represents a section of slate with the strip modification attached, andFig. 4 is a transverse section of Fig. 3.

A represents the slate proper, and a the slate-frame. l

A is the muflling-spring.

A2 represents the strip used in the modified form; a, the lacingstripfor same.

The frame a is perforated at intervals throughout its length,throughwhich the strip A is spirally laced in such manner as to bow over theedge of the frame-that is, stand out from the frame. In this example thestrip is returned, and the same process repeated in the oppositedirection, which latter adds to the effectiveness and appearance of themuffler, the perforations in thefralne being ofsuflicient size toreadily admit the two strips. The bows formed over the edge of theframe, in consequence of the spring-y nature of strips A, serve toproduce the desired result as a mufiler. The border piece or strip A2has a width sufficiently greater than the thickness of frame a toproject on each side of the latter. Strip A2 is perforated, as shown,through which the strip of cane, a, is inserted, for the purpose ofsecuring said strip A2 to the slate-frame. The latter is perforated, asin Fig. l, through which the strip a is laced, successively,with theperforation in strip A, thus securing the latter to frame a. Sufcientplay is allowed between frame a and strip A2 to admit of the requiredilexibility. y

Having thus fully described my said invention, what I claim, and desireto secure by Letters Patent, is

In combination with slate A and frame a, the ilexibly elasticspringmufller, substantially as described, and for the purposespecified.

JOSEPH RIDGE.

Witnesses:

L. C. STRAIGHT, CHARLEs O. HENTHORN.

